When you wire your backplanes, you have two options. You can "Daisy Chain" them together with short pieces of wire, or wire them "Dual Mono" as in the photo. Also note the green B+ wire that comes off the right top corner of the right backplane. This goes to the DCP as Joe explains in the wiring directions, but easily overlooked. This is best way to run this particular wire, rather than a long run all way back over to the cap.